1. Field of the Invention
The present invention concerns a machine and a method for dispensing fluid coloring products, or more simply colorants, for example liquids, into a base product for paints, varnishes, enamels, inks or suchlike, contained in a closed container, to obtain a finished product with a particular color tone. The latter is defined by a determinate formula, understood here as a sequence of delivery circuits to be activated and the corresponding delivery times, associated to the different colorants and in proportion with a particular volume of the base product. In particular, the machine and the method according to the present invention are able to optimize, in a programmed and automated manner, the overall delivery time (Tce) of the colorants as a function of the corresponding formula, using at the same time at most two delivery nozzles.
2. Description of Related Art
It is known that, in order to obtain a particular coloring product, such as for example a paint, we start from a base product, normally a neutral color or white, contained in a suitable closed container or tin, into which, after holing the lid, colored pigments are introduced, in relatively small quantities (usually not more than 10% in volume) by means of one or many nozzles, and according to a determinate dosage, so as to obtain the desired color tone.
From the European patent application EP-A-1439000 a machine is known for dispensing fluid coloring products each having a different color, to form a finished product with the desired color tone.
Currently, with the most advanced known machines, for example the one known as Corobox® produced and marketed by Applicant, it is possible to obtain more than 37,000 different color tones, combining a limited number of colored pigments, for example from 1 to 9, according to determinate formulas.
The above machine Corobox® is described in the international patent application WO-A-2011/161532 in the name of the Applicant, the content of which is incorporated here in its entirety.
Known machines for dispensing fluid coloring products, as defined above, normally comprise a number of tanks, in the range of ten and even more (for example 16), in each of which a determinate fluid coloring product or pigment or colorant is contained, with a determinate color, such as for example white, blue, red, cyan, yellow, magenta and black. Each tank or group of tanks containing a colorant of the same color is connected to a delivery circuit comprising a delivery nozzle and a motorized pumping member to selectively dose the coloring pigments in the desired quantity and to convey them toward the delivery nozzles.
The known technological solutions provide, as alternatives, either a so-called simultaneous dosage, in which all the delivery circuits associated with the coloring products to be delivered and calculated with the corresponding formula are activated simultaneously, or a so-called sequential dosage, in which only one delivery circuit is activated at a time. In this second case the different delivery circuits and the respective tanks are normally mounted on a rotatable support that is selectively made to rotate so as to take, on each occasion, a determinate delivery nozzle in correspondence with the container, which remains stationary in a determinate position.
In machines where the dosage is carried out simultaneously, each delivery circuit is controlled autonomously and independently by a corresponding electronic actuation circuit, so that the number of the latter is the same as that of the delivery circuits. This first type of machine, with simultaneous delivery, manages to obtain maximum productivity, and hence short overall delivery times, even if it has the disadvantage that it is complex and costly because it uses a number of electronic actuation circuits identical to the number of delivery circuits. In particular, in this first type of machine, the overall delivery time (Tce) is equal to the delivery time of the preponderant colorant (Tep).
In machines where the dosage is carried out sequentially, there is a single electronic actuation circuit, which activates the delivery circuit selected on each occasion. This second type of machine is simpler, but has the disadvantage that it has a rather low productivity, and hence rather high overall delivery times (Tce). In fact, in this second type of machine, the overall delivery time (Tce) is equal to the sum of the individual delivery times (Te1, Te2, . . . Ten) of all the fluid coloring products delivered, present in the corresponding formula.
Normally the formulas consist of three colorants, but they can reach a maximum of 16. There are also formulas with 1 or 2 colorants. For example, to obtain a determinate light red color, the typical formula is as follows: red colorant=40 ml; yellow colorant=15 ml; magenta colorant=4 ml, so that all in all 59 ml are delivered.
If we hypothesize that the pumping power of each pump associated with a tank is for example 10 ml/second, then the overall delivery time (Tce) in a simultaneous delivery machine is 4 seconds, while the overall delivery time of a sequential delivery machine is 5.9 seconds, given by the sum of 4 seconds to deliver the red color, plus 1.5 seconds to deliver the yellow, plus 0.4 seconds to deliver the magenta.